CaRhIn, CaRhIn 2 , and CaIrIn 2 were synthesized by reacting the elements in glassy carbon crucibles under an argon atmosphere in a high-frequency furnace. CaRhIn adopts the TiNiSi structure: Pnma, a = 730.0(4) pm, b = 433.1(2) pm, c = 828.8(4) pm, wR2 = 0.0707, 630 F 2 values, 20 variables. The CaRhIn structure consists of strongly puckered Rh 3 In 3 hexagons with Rh±In distances ranging from 273 to 276 pm. Due to the strong puckering each rhodium atom has a distorted tetrahedral indium environment. The calcium atoms fill the channels within the three-dimensional [RhIn] polyanion. CaRhIn 2 and CaIrIn 2 crystallize with a new structure type: Pnma, a = 1586.2(3) pm, b = 781.4(2) pm, c = 570.9(1) pm, wR2 = 0.0385, 1699 F 2 values, 44 variables for CaRhIn 2 , and Pnma, a = 1588.7(3) pm, b = 780.8(1) pm, c = 574.0(1) pm, wR2 = 0.0475, 1661 F 2 values, 44 variables for CaIrIn 2 . The structures of CaRhIn 2 and CaIrIn 2 can be described as an orthorhombically distorted rhodium respectively iridium filled CaIn 2 . The motif of transition metal filling is similar to that found in MgCuAl 2 type compounds CaTIn 2 (T = Pd, Pt, Au) and SrTIn 2 (T = Rh, Pd, Ir, Pt), but constitute a different tiling. Semi-empirical band structure calculations for CaRhIn and CaRhIn 2 reveal strong bonding In±In and Rh±In but weaker Ca±Rh and Ca±In interactions. Magnetic susceptibility and resistivity measurements of compact polycrystalline samples of CaRhIn 2 indicate weak Pauli paramagnetism and metallic conductivity with a room temperature value for the specific resistivity of 230 ± 50 lXcm.